Doomskar

Destroy all creatures.
Foretell {1}{W}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Coral Colony

Defender
{1}{U}, {T}: Target player mills X cards, where X is the number of creatures you control with defender. (To mill a card, a player puts the top card of their library into their graveyard.)

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Thwart the Enemy

Prevent all damage that would be dealt this turn by creatures your opponents control.

Haze of Pollen

Prevent all combat damage that would be dealt this turn.
Cycling {3} ({3}, Discard this card: Draw a card.)

Maddening Cacophony

Kicker {3}{U}
Each opponent mills eight cards. If this spell was kicked, instead each opponent mills half their library, rounded up.

Commencement of Festivities

Prevent all combat damage that would be dealt to players this turn.

Inspire Awe

Prevent all combat damage that would be dealt this turn except combat damage that would be dealt by enchanted creatures and enchantment creatures. Scry 2.

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Dovin, Hand of Control

Artifact, instant, and sorcery spells your opponents cast cost {1} more to cast.
−1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.

Fog of War

You gain 1 life for each creature on the battlefield. Prevent all combat damage that would be dealt this turn by creatures with power 3 or less.

White Sun's Twilight

You gain X life. Create X 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." If X is 5 or more, destroy all other creatures. (Players dealt combat damage by a creature with toxic 1 also get a poison counter.)

Root Snare

Prevent all combat damage that would be dealt this turn.

Folio of Fancies

Players have no maximum hand size.
{X}{X}, {T}: Each player draws X cards.
{2}{U}, {T}: Each opponent mills cards equal to the number of cards in their hand.

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Pause for Reflection

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Prevent all combat damage that would be dealt this turn.

Settle the Wreckage

Exile all attacking creatures target player controls. That player may search their library for that many basic land cards, put those cards onto the battlefield tapped, then shuffle.